8120 overclocked to 4.5GHz runs at 80C in Prime 95

I have overclocked my 8120 to 4.5 ghz on a evo 212 with dual cooling.
The temps are never going above 50 C when playing games, but go to 80 on prime 95.
Can I still keep the overclock if these temps never break 50C?

It depends on how CPU intensive the game is and how powerful your GPU is. If you have a low-med range gpu, and your playing a highly GPU dependent game (for example, playing Farcry 3 at Ultra settings 1080p with a HD 7850) you likely won't see a whole lot of difference.

That being said, the 8120 does get a nice performance boost from overclocking, so for more CPU dependent games, you will definitely get more frames, such as Borderlands 2 (a highly CPU dependent game)

My opinion is that you should not keep an overclock that can potentially harm your CPU even if its only under extreme situations. Now 80 is not overly extreme, but you should not exceed 70 on any CPU in an overclocked state for fear of damaging the hardware.

In this case, I would try and see if you can get the temps a bit more manageable under prime 95 by changing some fan directions and speeds to see if it helps. Then if you can't, drop the clocks down a slight bit.

The other thing is make sure your running on the lowest possible voltage setting for your CPU to be stable at that clock speed as that will reduce temperatures by a big margin.